Identification, Quantification, and Stereoselective Degradation of Triazole Fungicide Cyproconazole in Two Matrices through Chiral Liquid Chromatography-Tandem Mass Spectrometry

Systematic investigation of cyproconazole, including absolute stereochemistry, fungicidal activity, quantification in two matrices, and stereoselective degradation in cucumber, are conducted in this study. By virtue of the vibrational circular dichroism (VCD) spectroscopy, absolute configurations of four stereoisomers were identified to be (2 , 3 )-(+)-, (2 , 3 )-(+)-, (2 , 3 )-(-)-, and (2 , 3 )-(-)-cyproconazoles. Then, four stereoisomers exhibited stereoselective fungicidal activities against and , and the order of fungicidal activity was (2 , 3 )-(-)-stereoisomer ˃ the stereoisomer mixture ˃ (2 , 3 )-(-)-stereoisomer ˃ (2 , 3 )-(+)-stereoisomer ˃ (2 , 3 )-(+)-stereoisomer. Moreover, chiral liquid chromatography-tandem mass spectrometry was used to identify and quantify cyproconazole stereoisomers in soil and cucumber matrices. Good linearity ( ≥ 0.99) and recoveries (86.79-92.47%, RSD ≤ 3.94%) for them were achieved, respectively. Furthermore, stereoselective degradation of four cyproconazole stereoisomers was observed in cucumber and the order of degradation rate were (2 , 3 )-(+)-cyproconazole ˃ (2 , 3 )-(-)-cyproconazole ˃ (2 , 3 )-(+)-cyproconazole ˃ (2 , 3 )-(-)-cyproconazole. We envision that such systematic assessments of chiral fungicides at an enantiomeric level would provide valuable information in future studies involving enantioselective physiological, metabolic, and toxicological activities.